1. Field
One or more embodiments described herein relate to an organic light emitting display and a method for driving an organic light emitting display.
2. Description of the Related Art
An organic light emitting display has fast response speed and improved light emission efficiency, luminance, and viewing angle compared to other flat panel displays.
An organic light emitting displays generate images using pixels that emit light from organic light emitting diodes (OLEDs), which are self-luminous elements. Each pixel is connected to a data line and a scan line. The data line applies a data signal having emission information for the pixel. The scan line applies a scan signal, for example, to allow the data signals to be sequentially applied to the pixels.
In one type of organic light emitting display, pixels connected to a same data line are connected to different scan lines, and pixels connected to a same scan line are connected to different data lines. As a result, when the number of pixels in the display is increased to achieve higher resolution, the number of data lines or scan lines increases proportionally. As the number of data lines increases, the number of circuits in a data driver for generating and applying the data signals increases, which results in an increase in manufacturing costs.
Attempts have been made to reduce these costs. One attempt involves demultiplexing the data signals and then sequentially applying the data signals to the data lines. However, this attempt has proven to have significant drawbacks. One drawback relates to the inverse proportionality between one horizontal period and display resolution. Namely, a reduction of one horizontal period produces an increase in display resolution. The period in which the scan signal is to be applied in one horizontal period decreases under these circumstances.
A decrease in this period may prevent a compensation operation from being adequately performed for each pixel. For example, each pixel may include a compensation circuit to compensate the threshold voltage of its driving transistor. The compensation circuit may perform the compensating function in the period during which the scan signal is applied. However, when this period is reduced, a mura phenomenon may occur because it may be impossible to sufficiently compensate for the threshold voltages of the driving transistors in such a reduced period.